An energy management system (EMS) is a system of computer implemented tools used by operators of electric utility grids to monitor, control, and optimize the performance of the generation and/or transmission of an energy delivery system. In other words, an EMS optimizes, supervises and controls the transmission grid and generation assets. The monitoring and control functions are known as “supervisory control and data acquisition” (SCADA). Primary frequency control involves autonomous automatic actions by the EMS to arrest deviations in power system frequency whenever imbalances arise between load and generation. Primary frequency control actions are fast; they are measured in megawatt (MW)/seconds. Primary frequency control actions include governor response, load damping, and voluntary frequency-responsive load control, all of which contribute to frequency response. Secondary frequency control involves centrally coordinated actions by the EMS to return frequency to its scheduled value. Secondary frequency control actions are slower than primary frequency control actions; they are measured in MW/min. They are deployed both during normal operations and after primary frequency control resources have arrested frequency following major disturbances. Secondary frequency control actions include generation (or load) that responds to automatic generation control (AGC) signals or to operator dispatch commands. AGC is often referred to as “regulation” service.
In 2007, the Federal Energy Regulatory Commission (FERC) made compliance with the North American Electric Reliability Corporation's (NERC) reliability standards, which include control performance standard 001 (CPS1) and control performance standard 002 (CPS2) mandatory on registered entities pursuant to the new authorities for reliability, which had been given to the FERC by the United States Congress through the Energy Policy Act of 2005. Thus, Independent System Operators (ISOs) of electrical power networks are required to monitor and operate within certain power generation performance standards.
Beyond the CPS standards, the industry recognized that, from the standpoint of improving reliability, there are benefits to monitoring frequency error in time frames of less than one minute. This meant that practices which focus on managing area control error (ACE) and frequency over time frames of longer than one minute, would not, by themselves, be effective in ensuring reliability. For example, CPS1 does not provide strong incentives for short-term control because it is based on performance averaged over the course of an entire year. Since CPS1 was not intended to serve this purpose, the industry has developed the balancing authority ACE limit (BAAL) to address ACE and frequency excursions of shorter duration, as a supplement to CPS1. BAAL seeks to address all significant ACE and frequency deviations accounting for ACE diversity.
These performance standards determine the amount of imbalance that is permissible for reliability on power networks. Currently, ISOs operate by reacting to power trends as well as scheduled power interchange. Typically, operators provide regulatory agencies with schedule information detailing the quantity of energy and the time that energy will be produced. These schedules of energy vary over the course of a year, month, week, day, hour and other intervals of time such as seasons and special days such as holidays and weekends. Despite knowing that such energy requirements vary considerably at times, operators are often tasked with the burden of meeting demand for real-time and unanticipated shortage in energy. Having to meet these unanticipated demands is often the cause of increased energy costs. Under certain circumstances, energy costs may decrease when an oversupply of energy exists in the marketplace.
Thus, there is a significant need to comply with the control performance standards (CPS) (e.g., CPS1, CPS2, and BAAL) set by regulatory authorities such as the NERC. Therefore, what is needed are systems, methods and apparatus for improved management and control of energy delivery systems.